SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '23dbf63dd83284b13103792af6ae7ca2a7bc520e0a184be4bdf16df19fcc1d61' 
  AND token = 'm92Wct7ICs1HbMeQLoPdYGuMOyM3fp/gcL84EALV9ho=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}